FAYETTEVILLE, Ark. – If Zika-carrying insects were in the United States, the mosquitoes
that are associated with the virus don’t breed in rice fields, swamps or flood waters.
They breed closer to home, preferring bird baths, tires and other containers associated
with people and their dwellings, said Kelly Loftin, extension entomologist for the
University of Arkansas System Division of Agriculture.

WIGGLER -- Mosquito larvae. A week of rain and warm weather has encouraged mosquito
population growth in Arkansas. Taken June 3, 2014. (U of Arkansas System Division
of Agriculture photo by Mary Hightower)

However, there have been no instances of people acquiring the disease through mosquitoes
in the United States, according to the federal Centers for Disease Control and Prevention.
All reported cases to date involve acquiring the Zika out of the U.S., and being diagnosed
upon return. (see: http://www.cdc.gov/mmwr/zika_reports.html )

There is concern that the virus may become established in the United States.

“It’s important to learn to minimize mosquito bites and the risk of any mosquito-transmitted
disease,” Loftin said.

Two vectors

There are two potential mosquito vectors of the Zika virus, the Asian tiger mosquito
or Aedes albopictus; and Aedes aegypti.

“These two mosquitoes breed in artificial containers more closely associated with
people and their dwellings,” said Loftin. “Unlike mosquitoes commonly found in rice
fields which are active at night, Aedes aegypti and Aedes albopictus are active during the day.”

Although both mosquitoes may be present in Arkansas, “for mosquito-borne Zika transmission
to occur, potential mosquito vectors and Zika infected individuals must be simultaneously
present,” he said. So, the proportion of potentially virus infected mosquito vectors
would be small.”

The CDC said that only 4 percent of people traveling to Zika infected areas tested
positive for the virus. In an April 15 report only about 182 of 4,534 tested from
January to March of this year were positive for Zika (MMWR April 15, 2016, http://www.cdc.gov/mmwr/index.html).

Controlling the pest

The two mosquitoes prefer to breed in “small containers holding stagnant water such
as bird baths, old tires, catch basins under potted plants, and rain gutters that
hold water,” Loftin said. “Breeding source elimination around the home can be very
effective, especially when you consider that these mosquitoes have relatively short
flight ranges – a quarter to a half mile.

“Rid your yard of containers that hold water,” he said. “Flush bird baths daily and
don’t forget to check and fix rain gutters so water doesn’t stand in them. All sources
of standing water should be eliminated.”

Loftin also said that “the first line of defense against mosquito bites are insect
repellents. Those containing DEET are effective at repelling mosquitoes.”

Wearing a long-sleeved shirt and long pants will also reduce exposure to mosquito
bites. Gear and clothing can also be treated with clothing repellents that contain
permethrin. Look for these repellent names in various products and follow the use
label.

Rice fields

While many consider rice fields to be a breeding ground for mosquitoes, not all mosquitoes
are attracted to those areas.

Jarrod Hardke, extension rice agronomist with the University of Arkansas System Division
of Agriculture, said “there are more than thirty species of mosquitoes common to the
state of Arkansas. However, the main species found in Arkansas rice fields are Anopheles quadrimaculatus and Psorophora columbiae.

“You won’t find the mosquitoes that could transmit Zika virus out in the rice fields,
since they don’t develop in grassland or riceland pools, only in containers,” he said.

Loftin recommends using specific insecticides around the home to minimize the presence
of mosquitoes that live where people do. In addition to protective clothing and personal
repellents, fogging outdoor areas can be very effective.

“Fogging should be used only when mosquitoes are most active because they only last
two to three hours,” he said. “Treating areas such as shrubbery can be particularly
helpful in controlling resting mosquitoes.”

For more information about pest management, visit www.uaex.edu or contact your county extension office.

The University of Arkansas System Division of Agriculture offers all its Extension
and Research programs and services without regard to race, color, sex, gender identity,
sexual orientation, national origin, religion, age, disability, marital or veteran
status, genetic information, or any other legally protected status, and is an Affirmative
Action/Equal Opportunity Employer.